Summary

The purpose of this research is to determine the effectiveness of the novel H1Nl influenza
(inactivated/killed formulation) vaccine among both HIV-infected and HIV-uninfected persons.
The administration of the H1Nl vaccination is not part of the study's procedures, but is
being given as part of routine care.

Among those undergoing vaccination with the seasonal influenza vaccine during the current influenza season, to compare the presence of a positive seroresponse between HIV positive and negative persons

time frame:
1 year

To evaluate the effect of pre-existing anti-influenza immunity and recent history of seasonal influenza vaccination on seroresponses to the H1N1 influenza vaccine among both HIV positive and negative persons.

time frame:
1 year

To compare the durability of the H1N1 immunologic responses at 6 months post-vaccination between HIV-infected and uninfected persons.

time frame:
1 year

To evaluate the number of ILIs and documented influenza cases among HIV-infected and uninfected persons after initial vaccination, and to genetically characterize the influenza strains causing ILI events in our study cohort.

time frame:
1 year

To evaluate the impact of CD4 counts/percentages, HIV RNA levels, and HAART use on the immunologic responses to H1N1 vaccination in HIV positive subjects.

time frame:
1 year

To evaluate the impact of the H1N1 vaccine on CD4 counts/percentages and HIV RNA levels in HIV positive subjects.

Eligibility Criteria

Male or female participants from 18 years up to 50 years old.

Inclusion Criteria:
- 18-50 years of age
- Receiving the novel H1N1 vaccine (killed formulation) as part of routine clinical
care
- A military beneficiary who expects to remain in the local area for the next 6 months
Exclusion Criteria:
- Healthcare worker who is involved in direct patient care
- Acute febrile illnesses within 30 days prior to H1N1 vaccination (e.g., pneumonia,
influenza, ILI)
- Diabetes type 1 or type 2
- Systemic steroid or immunosuppressive medication use within 4 weeks of vaccination
- Active diagnoses of a cancer (non-melanoma skin cancer allowed).
- History of organ transplant
- Chronic active hepatitis B or C
- Active illicit drug use or alcohol abuse
- Blood transfusion within the last year
- Allergy to eggs
- Previous significant adverse reaction (e.g., anaphylaxis) to the seasonal influenza
vaccination
- History of serious reactions to any prior vaccination (e.g., Guillain Barre Syndrome
(GBS)).
- Received another vaccination in the last 4 weeks (receipt of seasonal influenza
vaccination is allowed)
- Among females of childbearing potential, pregnant or within 6 weeks of being
postpartum
- History of ILI which was confirmed as an H1N1 infection

Additional Information

The investigators study is being conducted to evaluate and compare the seroresponses of the
novel H1N1 vaccination among HIV positive and negative persons receiving the novel H1N1
vaccination as part of routine clinical care, with secondary objectives examining the impact
of prior seasonal vaccinations on subsequent seroresponse to the novel H1N1 vaccination,
determining potential reactions (local or systemic) to this new vaccine among patients, and
assessing for potential immunologic/virologic changes (in CD4/HIV RNA levels) after H1N1
vaccination among HIV patients. Finally, the investigators will collect data on
influenza-like illnesses (ILI) and H1N1 events during the study follow-up period and
influenza isolates causing ILI events will be genetically characterized.